摘要
目的探讨视黄酸(RA)对儿童淋巴结B细胞成熟分化的影响,及其与视黄酸受体基因表达水平变化的关系。方法本组24例,按年龄分为<1岁组、1～3岁组和～5岁组,每组8例。取患儿正常淋巴结分离细胞进行体外培养,分为RA组,RA+视黄酸受体α(RARα)拮抗剂(Ro415253)组(RA+Ro),脂多糖组(LPS),(LPS+RA)组和对照组。分别加入atRA、Ro415253、LPS。培养24、48h收集细胞。采用流式细胞术分析细胞表面标志,观察B细胞的成熟分化;RT荧光定量PCR测定视黄酸受体基因mRNA。结果<1岁组,RA组成熟B细胞的百分比明显高于对照组(24h:23%±5%vs17%±3%;48h:28%±6%vs22%±4%)(P均<0.05);LPS+RA组活化B细胞数明显高于LPS组(24h:82%±10%vs76%±8%;48h:83%±8%vs78%±10%)(P均<0.05)。同时,RARα基因表达水平也显著上调,而该受体拮抗剂可抑制RA的调节作用。1～3岁组淋巴结B细胞的成熟和活化呈现完全相同的调节变化,而～5岁组RA的这些调节作用不明显。结论RA能促进体外培养的淋巴结B细胞的分化发育和活化,该作用在3岁以下小儿明显。RARα基因的表达调节可能是介导RA作用的主要途径。
Objective To investigate the effect of retinoic acid on the differentiation and maturation of B cells from lymph node of children, and relational changes of the expression levels of retinoic acid receptor genes. Methods Twenty-four patients with digestive tract malformation underwent surgical operation in the surgical ward of our hospital. They were divided into 3 groups according to age: <1 yr, 1-3 yr, -5 yr, 8 cases in each age group. The lymph nodes in the margin of excised tissues were obtained. The cells separated from lymph nodes were cultured in vitro. The cells were divided into 5 groups: Retinoic acid (RA), RA plus Ro41-5253, RA receptor antagonist (RA+Ro), lipopolysaccharide (LPS), lipopolysaccharide plus RA (LPS+RA) and control, and were subjected to the corresponding treatments. After 24 h and 48 h of cell culture, the surface markers on the B cells were detected by flow cytometer to observe the maturation and activation of B cells. The expression levels of retinoic acid receptor genes were quantitatively analyzed by RT- fluorescent quantitative PCR. Results After culture, in <1 yr group, the number of the mature B cells (IgM +IgD +CD25 -) in the RA group was significantly higher than that in the control(24 h:23%±5% vs. 17%±3%;48 h:28%±6% vs. 22% ± 4%)(P<0.05), and that in the RA+RO group was not significantly different from that in the control (24 h:16% ±4%;48 h:20% ± 9%)(P>0.05). The number of activated B cells (IgM + CD25 +) in the LPS+RA group was obviously higher than that in the LPS group (24 h:82%±10% vs. 76% ± 8%;48 h:83% ± 8% vs. 78%±10%)(P<0.05). The level of RARα gene expression of B cells (lg copies/50 ng RNA) in the RA group was significantly higher than that in the control(24 h:7.03 ± 1.36 vs. 5.79 ± 2.05;48 h:7.91 ± 1.60 vs. 6.21 ± 1.88)(P<0.05), and that in the LPS+RA group was significantly higher than that in the LPS group(24 h:7.29 ± 1.53 vs. 5.98 ± 1.48;48 h:7.83 ± 1.66 vs. 5.79 ± 2.36)(P<0.05). In 1-3 yr group the changes of maturation and activation of B cells in the lymph nodes were the same as the <1 yr group. In -5 yr group, such changes were not significant. Conclusion RA can promote the development of B cell from lymph node in vitro culture in ≤3 yr children,which may be an important mechanism of vitamin A reinforcing the anti-infective immunity in young children. The expression and regulation of retinoic acid receptor genes may take part in the ontogenesis of B cell, and play a key role in the regulation of retinoic acid.
出处
《中华儿科杂志》
CAS
CSCD
北大核心
2005年第5期360-363,共4页
Chinese Journal of Pediatrics
基金
国家自然科学基金资助项目(30070661)
